Vehicle coolant pumps, often referred to as water pumps, have a ball bearing supported pump shaft that extends out of the pump housing through a coolant retaining seal. Some coolant normally leaks past the seal which, if it were not allowed to escape, could reach the shaft bearing. Therefore, the pump housing typically has coolant vent holes between the coolant seal and the shaft bearing. Without a drip collector of some sort, leaked coolant draining from the vent holes would fall to the ground, or perhaps puddle on some part of the engine block. While the normal, expected volume of coolant leakage presents no safety or operational problems, it is undesirable from an aesthetic stand point, and it could send a false signal regarding the condition of the coolant seal, precipitating an early and unnecessary replacement. Therefore, various drip collectors have been used, or proposed to catch and hold the vented coolant long enough for it to evaporate to the air. Such drip collectors typically take the form of a cup that rests beneath the coolant vent hole.
In one type of pump, the pump housing consists of two basic elements, a dish shaped stamping that is bolted to the engine and a cylindrical shaft bearing race that protrudes horizontally from the stamping. The vent holes are drilled through the bearing race, set back axially from a flat front face of the stamping. This type of pump housing lends itself well to a channel or gutter shaped drip collector of U-shaped cross section that surrounds the bearing race, covering the vent holes. One lip of the channel is radially spaced away from the bearing race, so that there is a continuous open evaporation path to the outside air. Leaking coolant runs down to the bottom of the channel, where it collects only until it is deep enough to overrun the lip of the channel. As such, the vast majority of the internal volume of the channel cannot actually be used to collect leaked coolant.